The countries in the agreement account for 58.7 percent of the world's emissions

Receive the latest national-international updates in your inbox

White bears costumed activists demonstrate near the Eiffel Tower, in Paris, Dec. 12, 2015 during the UN Climate Change Conference. The agreement goes into force Nov. 4 for the over 50 nations that have adopted it.

A landmark agreement on climate change will enter into force on Nov. 4, backed by a coalition of the world's largest polluters and small island nations threatened by rising seas.

U.N. Spokesman Farhan Haq said the EU, Canada and Nepal are all expected to deposit their instruments of ratification over the course of the day Wednesday, edging the percentage of emissions by ratifying countries past the 55 percent threshold needed for the treaty to take effect.

"I am delighted to announce that today the Paris Agreement will cross the second and final threshold needed for entry into force, and will enter into force on 4 November 2016," Secretary Ban Ki-moon said in a statement issued from Europe. "Global momentum for the Paris Agreement to enter into force in 2016 has been remarkable. What once seemed unthinkable is now unstoppable."

The deal takes effect 30 days after 55 countries, accounting for at least 55 percent of global emissions, have adopted it. Sixty-two countries had done so as of Tuesday but they accounted only for about 52 percent of emissions.

With the addition of Nepal, Canada and the seven EU countries that have so far ratified the deal, the countries now account for and estimate 58.7 percent of emissions.

A U.N. website said currently 72 of the 197 parties to the treaty, accounting for 56.75 of the world's greenhouse gas emissions have officially ratified. It wasn't clear if all the parties that had planned to deposit their ratifications Wednesday, which may account for the discrepancy.

"It's clearly a momentous moment in terms of global action on climate change," said David Waskow, international climate director at World Resources Institute. "This has been much more rapid than anticipated and demonstrates political support for the agreement."

The Paris agreement commits rich and poor countries to take action to curb the rise in global temperatures that is melting glaciers, raising sea levels and shifting rainfall patterns. It requires governments to present national plans to reduce emissions to limit global temperature rise to well below 2 degrees Celsius (3.6 degrees Fahrenheit).

Suspect in Georgia Officer Shooting Dead

Authorities announced the death of Minquell Kennedy Lembrick, 32, on Dec. 8, 2016 after a manhunt stemming from a domestic abuse call at an Americus, Georgia apartment. (Published Thursday, Dec. 8, 2016)

While the targets in the agreement are not legally binding, the treaty does require countries to report on emissions and their progress on reaching the goals in the national climate plans they submitted to the U.N. The countries are also required to maintain those plans, update them every five years and to pursue measures to implement their stated goals.

The accord, which was adopted by consensus on Dec. 12, 2015, has entered into force at what is considered in the world of international diplomacy, a blistering pace, reflecting a sense of urgency in the fight against global warming and a desire to seal the deal before Secretary General Ban Ki-moon and U.S. President Barack Obama leave office.

"There's a lot of hard work ahead to fulfill the main Paris goal, avoiding dangerous climate change. Without focused efforts starting now, we are not going to avoid falling over a very steep cliff," Oppenheimer said in an email.

Watch: Senators Pay Tribute to Joe Biden With Speeches

Vice President Joe Biden was honored with an emotional bi-partisan tribute on the Senate chamber floor on Dec. 7. 2016. Senators on both sides of the aisle were on the same page as they stepped up to express their admiration and gratitude to the outgoing vice president. An emotional Biden sat in the presiding chair during the moving tribute, which latest for more than two hours as lawmakers celebrated their colleague. (Published Thursday, Dec. 8, 2016)